JPH0916907A - Thin-film magnetic head and its manufacture - Google Patents

Abstract

PURPOSE: To obtain a low-impedance-noise thin-film magnetic head. CONSTITUTION: The thin-film head is constituted by laminating an insulating film 2, magnetic cores 3, 9, and 12, and a coil 7 on a substrate 1 in order. The coil 7 is formed etching the insulating film 2 to form a coil groove 7a and then embedding a conductor film in the coil groove; and the thin-film head has a stopper film 18 for groove depth control at the coil groove etching, and the formation range of the stopper film 18 on a lower core 4 is limited to the area sandwiched almost between the upper and lower cores 4 and 12, thereby overetching the insulating film by a specific quantity at the coil groove etching. Consequently, the coil groove depth in an area where the stopper film is not present is made deeper than the coil groove depth of the area where the stopper film 18 is present to lower impedance noise.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film magnetic head suitable for use in a magnetic recording / reproducing apparatus such as a magnetic disk and a method for manufacturing the thin film magnetic head.

[0002]

2. Description of the Related Art A thin film head (Japanese Patent Laid-Open No. 4-89609) suitable for high-density magnetic recording proposed by the applicant of the present invention has a large DC resistance due to the small cross-sectional area of the coil conductor. Therefore, the impedance noise is large, and the heat generated by energization at the time of recording is large, so that the member around the coil is distorted by the heat and cracked, resulting in lack of reliability.

In order to solve this drawback, a thin film head proposed by the present applicant thereafter (Japanese Patent Application No. 6-86040).
19 is shown in FIG. 19, but as seen in the example (FIGS. 3 to 11), the number of steps is increased, which is disadvantageous in terms of cost. Further, it is difficult to accurately align the coil formed first and the coil formed later.

The conventional method of manufacturing the thin film head will be described below with reference to the drawings. In these figures, 1 is a substrate, 2 is an insulating layer, and 4 is a lower core made of a soft magnetic material. Reference numeral 5 denotes an insulating layer, and the coil conductor 7 is wound and embedded in the insulating layer 5. 9 is an intermediate core, 1
0 and 11 are insulating layers, and 12 is an upper core.

First Manufacturing Step (FIG. 3) For example, a soft magnetic film containing Fe, Co, and Ni as main components is formed on the substrate 1, and the lower core 4 is formed by a photolithography step and ion milling. In addition, in order to avoid complexity, the substrate 1 is not shown in FIG. It is also omitted in each of the subsequent drawings (B).

Second manufacturing process (FIG. 4) An insulating layer 2 made of SiO ₂ , TiO ₂ , Al ₂ O ₃ or the like is formed to be thicker than the thickness of the lower core 4 by sputtering, vapor deposition, ion plating or the like, and is polished. The surface is formed flat in a process or the like.

Third manufacturing process (FIG. 5) A groove is formed in the insulating layer 2 in a circular shape by a photolithography process and an etching process, and a conductor film of Cu or the like is formed in the groove by vapor deposition or the like and flattened by polishing. It is on the lower layer side of the coil conductor 7. Here, mask pattern formation, coil groove etching, conductor (Cu) vapor deposition, and planarization polishing are performed.

Fourth manufacturing step (FIG. 6) The lower core 4 is left with the portion where the intermediate core 9 on the rear side is formed being left.
SiO ₂ becomes the top surface and the magnetic gap G, to form a non-magnetic layer 8 made of TiO ₂ or the like, an intermediate of the soft magnetic film of Fe in the same manner as in the first manufacturing step to the top, Co, and Ni as a main component The cores 9 and 9 are formed at predetermined intervals. And
The insulating layer 5 is formed on the other portion where these intermediate cores 9 and 9 are left. Here, a gap and an intermediate core are formed.

Fifth Manufacturing Step (FIG. 7) A spiral groove 7a is formed on the upper surface side corresponding to the coil conductor 7 already formed on the lower layer side and the upper surface side on the lower core 4 by a photolithography process and an etching process. To do. Particularly, the groove 7a is formed so as not to reach the upper surface of the lower core 4 at the upper surface position of the lower core 4. Here, mask pattern formation and coil groove etching are performed.

Sixth Manufacturing Process (FIG. 8) A groove 7a in which the lower layer coil conductor 7 is formed is further formed so as to reach the coil conductor 7 by a photolithography process and an etching process. Similarly, groove 7a
A conductor film of Cu or the like is formed over the entire area of. In order to form the coil conductor 7 without displacement between the lower layer and the upper layer, it was quite difficult to control the accuracy. Here, mask pattern formation, coil groove additional etching, conductor (Cu) vapor deposition, and planarization polishing are performed.

Seventh Manufacturing Step (FIG. 9) An insulating layer 10 made of SiO ₂ , TiO ₂ or Al ₂ O ₃ is formed on the portion excluding the intermediate cores 9, 9.

Eighth Manufacturing Process (FIG. 10) On the upper surface region corresponding to the lower core 4, on the intermediate cores 9, 9 and the insulating layer 10, the upper core 12 is formed in the same manner as the first manufacturing process.
To form The insulating layer 1 is left with the upper core 12 left.
Form one.

Ninth manufacturing process (FIG. 11) The insulating layers 10 and 11 are provided with a conductor 13 which is a contact hole.
And a lead portion 14 connected to the coil conductor 7 through the conductor 13 is formed as a Cu layer into a predetermined shape by etching. Then, as shown in FIG.
5, the alloy layer 16 is sequentially provided, and further, predetermined processing is performed so that the magnetic gap G becomes an end from the cutting line BB ′, the lead wire 17 is provided, and the thin film magnetic head is completed.

G is a gap, and 13 is the coil conductor 7.
And a lead portion 14 is continuously formed on the conductor 13. Reference numeral 15 denotes a pad portion, on the upper surface side of which an alloy layer 16 is provided, and a lead wire 17 is pressure-bonded to the alloy layer 16 to form one head element. According to the thin-film magnetic head having such a configuration, impedance noise is low, and a method of manufacturing a head suitable for recording / reproducing on a narrow track or a narrow pitch can be obtained.

[0015]

However, in the structure described above, the impedance noise can be reduced without increasing the number of windings even when the thickness between the upper and lower cores is limited. As seen in the examples (Fig. 3
(FIG. 11) The number of steps is increased, which is disadvantageous in terms of cost.

Therefore, the present invention provides a method of manufacturing a thin film magnetic head capable of reducing the DC resistance of a coil without reducing the number of windings and the number of steps, and impedance noise. It is possible to expect effects such as reduction of the temperature, high-S / N recording / reproducing, reduction of heat generation of the coil and realization of a highly reliable head.

[0017]

In order to solve the above-mentioned problems, the thin-film magnetic head and the manufacturing method thereof according to the present invention are constituted by the following means. That is, in a thin film magnetic head in which an insulating film, a magnetic core, and a coil are sequentially laminated on a substrate, the coil is formed by etching the coil groove in the insulating film and then embedding the conductor film in the coil groove. A thin film head with a stopper film is used to control the depth of the groove during etching, and the stopper film formation range on the lower core is defined as a region between the upper and lower cores. By doing so, the depth of the coil groove in the region without the stopper film is formed deeper than the depth of the coil groove in the region with the stopper film, and an insulating film and a magnetic core on the substrate. In a method of manufacturing a thin film head, in which coils are sequentially laminated, the coil is formed by etching a coil groove in an insulating film and then forming a conductor film in the coil groove. A method for manufacturing a thin-film magnetic head having a stopper film for controlling the groove depth during coil groove etching by embedding is performed, and the stopper film formation range on the lower core is defined as a region substantially sandwiched between the upper and lower cores. Manufacture of a thin film magnetic head characterized in that the depth of the coil groove in the region having no stopper film is made deeper than the depth of the coil groove in the region having the stopper film by performing a predetermined amount of over-etching at the time of groove etching. Method.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the method of manufacturing a thin film magnetic head of the present invention will be described below with reference to the drawings. FIG.
FIG. 2 is a schematic partial cross-sectional perspective view of a thin film magnetic head according to the embodiment, and FIG. 2 is a view showing only a core portion and a coil pattern.
(A) is a schematic perspective view, (B) is a plan view, (C) is (B).
3 is a sectional view taken along line AA ′ of FIG. The same components as those of the conventional example are designated by the same reference numerals, and detailed description thereof will be omitted.

In these figures, 1 is a substrate, 2 is an insulating layer, and 4 is a lower core made of a soft magnetic material, and is formed with a thickness of about 1 to 9 μm. Further, a stopper film 18 is formed on the upper surface of the lower core 4 to have a thickness of about 1 μm. Intermediate cores 9 and 9 having substantially the same thickness are provided on the front and rear portions of the upper surface of the lower core 4, and the stopper film 1 is provided on the upper surfaces of these intermediate cores 9 and 9, respectively.
8, the upper core 12 is formed so as to sandwich the insulating layers 5 and 10.

Reference numeral 7 is a coil conductor, and a spiral pattern is formed so as to wind the intermediate core 9 on the rear side. The coil conductor 7 has a height sufficiently low to be embedded in the insulating layer 5 in the region between the cores, and the height is different in the outer region between the cores, and the insulating layer 2 further below the insulating layer 5 has a different height. Has reached approximately twice the height between the cores.

A conductor 13 is connected to the coil conductor 7 and is continuous with the lead portion 14 via the insulating layers 10 and 11. Reference numeral 15 denotes a pad portion, on the upper surface side of which an alloy layer 16 is provided, and a lead wire 17 is pressure-bonded to the alloy layer 16 to form one head element.

Next, a method of manufacturing the thin film magnetic head having the above structure will be described with reference to FIGS. 3, 4, and 9 to 15. In these figures, (A) shows a schematic sectional view and (B) shows a schematic partial plan view. Forming the lower core,
Each step of flattening with the insulating film is the same as the manufacturing steps (first manufacturing step, second manufacturing step) shown in FIGS.

First Manufacturing Step (FIG. 3) A soft magnetic film containing, for example, Fe, Co, and Ni as main components is formed on the substrate 1, and a lower core 4 is formed by a photolithography step and ion milling. In addition, in order to avoid complexity, the substrate 1 is not shown in FIG. It is also omitted in each of the subsequent drawings (B).

Second manufacturing step (FIG. 4) An insulating layer 2 made of SiO ₂ , TiO ₂ , Al ₂ O ₃ or the like is formed to be thicker than the thickness of the lower core 4 by sputtering, vapor deposition, ion plating or the like, and polished. The surface is formed flat in a process or the like.

Third manufacturing process (FIG. 12) After the lower core 4 is embedded and flattened, Al ₂ O ₃ and ZrO _{2 are formed.}
The stopper film 18 such as is formed to a thickness of, for example, about 1 μm. Next, the stopper film is removed using a means such as ion milling while leaving the formation region of the intermediate core above the lower core 4.

The area where the stopper film 18 is left is shown in FIG.
As shown in FIG. 2 (B), it is necessary to make it slightly wider (about 1 to 5 μm) than the region of the lower core 4. By this step, the stopper film 18 is formed in the desired region. This step may be performed by a lift-off process.

Fourth manufacturing process (FIG. 13) The lower core 4 is left behind except for the portion where the intermediate core 9 is formed.
On the upper surface of SiO ₂ and TiO to form a magnetic gap 8 (G)
A non-magnetic layer 8 such as ₂ is formed, and an intermediate core 9 is formed on the upper surface in the same manner as in the steps of FIGS. 3 and 4, and an insulating layer (insulating film) is formed.
Embed with 2 and flatten. Here, the gap and the intermediate core are formed.

Fifth X manufacturing process (FIG. 14) Next, the intermediate core 9 on the rear side is surrounded,
The spiral coil groove 7a is formed by a photolithography process and an etching process. In this etching step, after the coil groove 7a reaches the stopper film 18 on the lower core 4, overetching is performed for a predetermined time, so that the etching process shown in FIG.
As shown in, the groove in the portion without the stopper film 18 is
It is possible to dig deeper as compared with the portion having the stopper film. Here, the mask pattern is formed and the coil groove is etched.

A specific example of how deeply the coil groove 7a can be dug will be described below. When reactive ion etching using CHF ₃ as an etching gas and the power density is 1.7 W / cm ² , for example, SiO ₂ , Al ₂ O
The etching rates of ₃ and ZrO ₂ are approximately 1000 Å / min, 200 Å / min, and 100 Å / min, respectively.

When the stopper film thickness is 1 μm, the remaining film thickness is 0.5
When etching is performed up to μm, the over-etching time is 25 min for the Al ₂ O ₃ stopper film and 50 min for the ZrO ₂ stopper film. At this time, the etching depths of SiO ₂ are 2.5 μm and 5 μm, respectively.

Therefore, when Al ₂ O ₃ is used and the SiO ₂ film thickness on the stopper film is 2 μm,
By performing over-etching for 25 minutes, the depth of the coil groove 7a on the stopper film becomes 2.5 μm, and the depth of the coil groove in the other regions becomes 5 μm. Compared with the case where the stopper film is formed over the entire area. 40% coil resistance
It can be reduced to some extent (when the coil length on the stopper film is estimated to be 25% of the total).

Sixth manufacturing process (FIG. 15) A conductor film of Cu or the like is formed in the coil groove 7a by vapor deposition or the like, and is flattened by polishing to form the coil conductor 7.
Here, conductor (Cu) vapor deposition and planarization polishing are performed.
The subsequent manufacturing steps are almost the same as the seventh to ninth manufacturing steps shown in FIGS. 9 to 11 which have already been described.

Seventh manufacturing process (FIG. 16) An insulating layer 10 made of SiO ₂ , TiO _2, Al ₂ O ₃ or the like is formed on the portion excluding the intermediate cores 9, 9. A stopper film 18 is formed on the upper surface of the lower core 4.

Eighth manufacturing process (FIG. 17) In the upper surface region (the surface where the stopper film 18 is formed) corresponding to the lower core 4, on the intermediate cores 9 and 9 and the insulating layer 10,
Similar to the first manufacturing process, the upper core 12 is formed. Then, the insulating layer 11 is formed with the upper core 12 left.

Ninth manufacturing process (FIG. 18) Conductors 13 which are contact holes are provided on the insulating layers 10 and 11.
And a lead portion 14 connected to the coil conductor 7 through the conductor 13 is formed as a Cu layer into a predetermined shape by etching. Then, as shown in FIG.
5. The bonding pad 16 is sequentially provided, and further, predetermined processing is performed, cutting is performed so that the magnetic gap G becomes an end from the cutting line BB ', and the lead wire 17 is provided to complete the thin film magnetic head. To do.

As described above, according to the method of manufacturing the thin film magnetic head of the present embodiment, the height (thickness) of the coil conductor 7 in the region outside the core is substantially smaller than the height (thickness) inside the core. Since it is doubled, the cross-sectional area is also approximately doubled, and the resistance value in this region is approximately halved.

The ratio of the part of the coil conductor 7 embedded in the core to the whole coil conductor is about 10 to 30%, and the ratio of the part of the coil conductor 7 embedded is 1/4 of the entire coil conductor. If so, the coil conductor 7
The resistance value of is about 60% of the conventional value.

Therefore, according to the method of manufacturing the thin film magnetic head of the present embodiment, it is possible to obtain a highly reliable thin film magnetic head with low impedance noise even when the thickness of the intermediate core is limited. I can.

Further, in the magnetic head of the above-mentioned embodiment, the coil conductor 7 is a one-layer winding pattern, but in the case of a winding pattern of two or more layers, the coil conductor of the first layer is used. The present invention may be applied to No. 7.

[0040]

According to the thin-film magnetic head and the method of manufacturing the same of the present invention, impedance noise can be reduced without increasing the number of windings, especially when there is a restriction on the thickness between the upper and lower cores. It is possible to provide a thin film magnetic head and a method of manufacturing the same, which is highly accurate and reliable.

Comparing the number of steps, it is only necessary to form the stopper film in the region sandwiched by the upper and lower cores, and it is not necessary to add a coil step again as in the conventional example and to perform again, and a substantially equivalent coil shape is obtained. Therefore, the man-hours can be significantly reduced.
In addition, since the coil is formed in a single process, it is not necessary to accurately align the coil formed first and the coil formed later as in the conventional case, the yield is improved, and heat generation can be suppressed. I can.

[Brief description of the drawings]

FIG. 1 is a schematic partial cross-sectional perspective view of a thin film magnetic head of the present invention.

FIG. 2 is a view showing only a core portion and a coil pattern.

FIG. 3 is a diagram showing a first manufacturing process of the method of manufacturing the thin film magnetic head.

FIG. 4 is a diagram showing a second manufacturing process.

FIG. 5 is a diagram showing a third manufacturing process.

FIG. 6 is a diagram showing a fourth manufacturing process.

FIG. 7 is a diagram showing a fifth manufacturing process.

FIG. 8 is a diagram showing a sixth manufacturing process.

FIG. 9 is a diagram showing a seventh manufacturing process.

FIG. 10 is a diagram showing an eighth manufacturing process.

FIG. 11 is a diagram showing a ninth manufacturing process.

FIG. 12 is a third embodiment of the method of manufacturing a thin film magnetic head of the invention.
It is a figure which shows a manufacturing process.

FIG. 13 is a diagram showing a 4X manufacturing process according to the present invention.

FIG. 14 is a diagram showing a 5X manufacturing process according to the present invention.

FIG. 15 is a diagram showing a 6X manufacturing process according to the present invention.

FIG. 16 is a diagram showing a 7X manufacturing process according to the present invention.

FIG. 17 is a diagram showing an eighth manufacturing process of the present invention.

FIG. 18 is a diagram showing a ninth manufacturing process of the present invention.

FIG. 19 is a schematic partial cross-sectional perspective view of a conventional thin film magnetic head.

[Explanation of symbols]

 1 Substrate 2, 5, 10, 11 Insulating Layer (Insulating Film) 4 Lower Core 7 Coil Conductor 7a Coil Groove 8, G Gap 9 Intermediate Core 12 Upper Core 13 Conductor 14 Lead Part 15 Pad Part 16 Bonding Pad 17 Lead Wire 18 Stopper film

Claims (2)

[Claims] 1. A thin film magnetic head comprising an insulating film, a magnetic core and a coil which are sequentially laminated on a substrate, wherein the coil is formed by etching a coil groove in the insulating film and then burying a conductor film in the coil groove. In order to control the depth of the groove when etching the coil groove, a thin film magnetic head having a stopper film is configured, and the formation range of the stopper film on the lower core is set to a region substantially sandwiched between the upper and lower cores, and the coil groove is etched. Sometimes by performing a predetermined amount of over-etching,
A thin film magnetic head, wherein the depth of the coil groove in the region without the stopper film is formed deeper than the depth of the coil groove in the region with the stopper film. 2. A method of manufacturing a thin film magnetic head comprising a substrate on which an insulating film, a magnetic core and a coil are sequentially laminated, the coil being formed by etching a coil groove in the insulating film, and then forming a conductive film on the coil. A method of manufacturing a thin-film magnetic head having a stopper film for controlling the depth of the groove when the coil groove is etched by embedding in the groove, and the formation range of the stopper film on the lower core is defined as a region substantially sandwiched between the upper and lower cores. A thin film characterized in that the depth of the coil groove in the region without the stopper film is formed deeper than the depth of the coil groove in the region having the stopper film by performing a predetermined amount of over-etching at the time of etching the coil groove. Magnetic head manufacturing method.